Fabrication of polycrystalline TiO 2 nanopatterns by TiO 2 sol base imprint lithography

Abstract

This paper reports a process for fabricating TiO 2 nano-patterns using nanoimprint lithography and a sol–gel method. An ethanol-based TiO 2 sol was prepared using tetrabutylorthotitanate as a precursor and used as an imprint resin. A replicated polydimethylsiloxane (PDMS) mold was used as an imprint stamp. During the imprinting process at 5 atm and 200 °C for 1 h, the TiO 2 sol changed to a TiO 2 gel by absorbing the solvent into the PDMS mold. After imprinting, a TiO 2 gel pattern was formed on an oxidized Si wafer. After subsequent annealing, it confirmed that patterns of the master template were transferred to TiO 2 patterns by Scanning Electron Microscopy. Furthermore, Transmission Electron Microscopy and X-Ray Diffraction showed that the TiO 2 gel patterns had been converted to an inorganic polycrystalline TiO 2 pattern.